Underreamer



June 18, 1929.

W. HARGREAVES UNDERREAMERY Filed May 7, 1928 2 Shets-Sheet l Inventar Attormgy June 18, 1929. w. HARGREAVES 1.717.559

UNDERREAMBR Filed May 7, 1928 2 Sheets-Sheet 2 Inventor W fiZyrem/m mwmw Attorney Patented June 18, 1929.

UNITED STATES PATENT oFFicE,

WILLIAM HARGREAVES, or LONG BEAGH, CALIFORNIA, 'assrelvonf'ro THAD'DEUS 3.,

PRICE, or BA'rnsvILLn, TEXAS. I g

UNDERREAMER.

Application filed May 7, 1928. Serial No. 275,851.

The present invention relates to improvements in earth working implements and has reference more particularly to an underreamer.

One of the important objects of the present invention is to provide an underreamer that is adapted tobe passed downwardly in a well casing, a series of reamer blades being pivotally and slidably associated at their upper ends with the body of the reamer, resilient means being interposed between the body and the lower free end portions of the blade for normally urging the same outwardly when the reamer blades are disposed below the lower end of the casing, additional means being provided for locking the blades in lowered outwardly disposed position.

A further object of the invention is to provide an underreamer which includes a re.- movable fish tail bit for association with the lower end of the body.

Still a further object is to provide an underreamer of the above mentioned character, which is simple in construction, inexpensive, strong and durable, and further well adapted to the purpose for which it 1s designed.

Other objects of the invention will become apparent as the nature of the invention proceeds, and when taken in connection with the accompanying drawings.

In the accompanying drawings:

Figure 1 is a side elevation of the under reamer embodying'my invention, showing the position of the blades, while the reamer is being passed downwardly through a well casm Figure 2 is a similar view, showing the position of the blades when the reamer body is disposed below the lower end of the well casing, and also showing the manner in which the pivoted blades are locked in their outwardly disposed positions.

Figure 3 is a transverse section taken approximately on the line 33 of Figure 1, looking upwardly.

Figure 4 is a similar section taken approximately on the line 44 of Figure 1, looking downwardly, and

Figure 5 is a transverse section taken on the line 5-5 of Figure'Lalso looking in a downward direction, and a a v t Figure 6 isa detail perspective view of one of the present invention.

In the drawings, wherein for the purpose of illustration is shown the preferred embodiment of my invention, the numeral 1 designates generally my improved underreamer, the same comprising an elongated solid body,

of the reamer blades, forming a salient part.

the intermediateportion of which is so constructed as to form the flat faces 3, three of g r such faces being provided, whereby aytriangular formation is formed, as sh0wn-;more clearly in Figures *3, 4t, and 5 of the drawings.

As shown in Figures 1 and 2, these .flat faces are not continuous, the same being interrupted at-the intermediate portions thereof.

The lower end of the cylindrical body is formed with an internally threaded socket 4,

forreceiving the threaded shank 5 of the fish tail 6}, so that said bit can be readily attached or disengaged. The upper end of the body is formed witha threaded projection 7 for connection'to the lower end of the drill rod, in the manner well known in the art. The body of the reamer is formed with a fluid passage 8 in the upper end, and the same extends centrally through the threaded extension 7. Radial passages 9 extendfrom the lower end of the central vertical passage 8,

to the upper ends of the respective flattened provision of a series of reamer blades, one

of which. is shown in detail in Figure 6. Each blade which is designated generally by the nun'ieral 13 is of a flat piece of metaland comprises the blade or earth engaging portion 14 from which extends upwardly the elongated shank 15. The lower end of the'earthengag face 3"is stop forming lug'22 for engage ing portion of the blade is cut away as at 16, and an enlargement 171s formed at the inner edge portion of the earth engaging portion 14 at the upper part thereof and an angular slot 18 is formed in the enlarged portion 17. A longitudinally extending slot 19 is formed in the upper end portion of the shank and as is further shown in Figure 6, the upper end of the shank is slight yrounded. These blades o,

in Figures 1 and 20f the drawings. The

headed pin or screw 20 .is threaded into a threaded opening provided therefor in each fiat face, adjacent the upper end thereof and theshank of each screw extends through the slot 19 of the respective blade, and thus provideswa slidable and pivotal connection for the upper end of each reamer blade on the body'2.

Additional. headed bolts 21 are threaded in threaded sockets provided therefore in the respective flat faces 13 at a point below the cylindrical, portion 10 which intersects the flat faces, and these headedpins or bolts 21 are operable in the slots 18"of the respective reamer blades for a purpose also to be present ly described in detail.

- Also secured on this portion of each fiat nent'with theinneredge of the lower portion of theshanlr of each blade to limitthe inward swinging movement of the reamer blades.

The earth engaging portions 14 of the pivby the action of the leaf springs 28. One leaf springis provided for each blade and the up- "per end of the leaf spring is secured within a suitable recess provided therefor 1n the lower portionof the shoulder 10, the lower end of eachspring being bowed inwardly for engagement with theinner edge of the shoulder or enlargement 17 of the blade, as indicated in the drawings, i r V r When the underreamer is in the act of being lowered downwardly in the well casing A, the blades 13 are in their lowermostposition, so that the headed bolts 20 will be disposed in the uppermost ends of the slots 19,

whilethe headed, bolts 21 wil be in engagement with the outer endsof the horizontally disposed portions of the angular slots 18 and the blades will be confinedwithin their respective slots, by reason of the inner wall of the well casing engaging the outer edges of the blade, as clearly shown in'Figure 1.

As soon as the underreamerpasses beyond the lower end of the well casing,the springs 23w1llforce the pivoted reamer blades outwardly to an operative position and furtherdownward movement of the body of the reamer will result in the bolt 20 moving downwardly to the lower end of the slot 19 and in the meantime, the headed bolt 21 will have been moved to the lower ends of the vertical. portions of the angular slotslS, thus positively locking theblades in their outwardly disposed position and ready for use. 1

By raising upwardly on'the body 2, the bolt will again assume the position shown in Figure 1,"so that when the reamer is pulled up- 'wardly through the well casing, the well casing will move the pivoted reamer blades inwardly for disposition in the respective slots and hold the same in the position also shown to an inoperative and operative position respectively, n an automatic manner, and fur thermore, the locking means will also be automatic. 7 The simplicity of my improved 'underreamer enables the same to be constructed at a very low cost, and the parts can be readily replaced whenever necessary without requiring the complete destruction of the underreamer.

While I have shown the preferred embodiment of my invention, it is to be understood that various changes in the size, shape and arout departing from the spiritof the inven a v I ltion and the scope of the appended olaim.

V oted blades are normally urged outwardly rangement of parts may be resorted to, with- Having thus described my invention, what a I claim as new is:

In an underreamer of the class described, an elongated body having a series of flat elongated faces, upper and lower shoulders formed on each flat face, said shoulders being slotted longitudinally adjacent the respective flat face of the body, a plurality of reamer lades each including an earth engaging portion, an upwardly extending shank, the shank being formed with a longitudinal slot inits upper end, the earth engaging portion being I slots formed in the shoulders on the respective i flattened faces of the body and being capable of outward swinging movement to an operative position when the last mentioned headed bolts are disposed in the forward ends of the horizontal disposed portions of the annular I slots, leaf springs secured at their upper bolts being disposed in the lower portions of ends in the lower portions of the respective the angular slots to lock theblades in an out-v shoulders the free ends of the leaf springs Wardly disposed operative position when thef I bearing against the inner edge portions of the body is moved downwardly.

5 respective earth engaging portion of the In testimony whereof I aflix my signature.

blades to urge the same outwardly with respect to the body, said last mentioned headed WILLIAM HARGREAVES. 

